An organic electroluminescence (hereinafter, referred to as “organic EL”) display device includes a light-emitting element in each of a plurality of pixels, and displays an image by controlling light emission in each of the pixels individually. The light-emitting element includes a pair of electrodes, one of which is an anode electrode and the other of which is a cathode electrode, and a layer containing an organic EL material (hereinafter, referred to also as a “light-emitting layer”) held between the pair of electrodes. When electrons are injected into the light-emitting layer from the cathode electrode and holes are injected into the light-emitting layer from the anode electrode, the electrons and the holes are recombined. Light emitting molecules in the light-emitting layer are excited by extra energy released by the recombination, and then are deexcited. Thus, the light-emitting elements emit light.
In such an organic EL display device, the anode electrode in each of the light-emitting elements is provided as a pixel electrode corresponding to the respective pixel, and the cathode electrode is provided as a common electrode corresponding to the plurality of pixels and supplied with a common potential. The organic EL display device applies a potential of the pixel electrode in each pixel with respect to the potential of the common electrode, and thus controls the light emission of each pixel.
Recently, flexible display devices including a foldable display region have been actively developed. In such a flexible display device, lines are formed in a display region. There is a problem that when the display device is folded, a stress is concentrated on the lines, and the lines are easily disconnected. A gate insulating layer included in a transistor, an interlayer insulating layer covering the transistor, and the like are easily cracked when the display device is folded and thus easily decline the reliability.
Japanese Laid-Open Patent Publication No. 2010-020209 discloses a liquid crystal display device including an array substrate and a color filter substrate that are located such that surfaces thereof face each other and are bonded together by a sealing member. A space between the array substrate and the color filter substrate is filled with a liquid crystal material. On the surface of the array substrate, a common line is formed in a peripheral region around a display region. The common line has light transmission holes in a mesh pattern, and the sealing member is located so as to overlap the light transmission holes located in the mesh pattern as seen in a plan view.